Control system for classification yards



June 30, 1936. I

-' N. c, L. BROWN CONTROL SYSTEM FOR CLASSIFICATION YARDS Filed July 31,1951 5 Sheets-Sheet 1 Fags is Mam f Jim, ATTQRN'EY June so, 1936. N. c.1.. BROWN 5,69

I I CONTROL SYSTEM FOR CLASSIFICATION YARDS Fil ed July 31, 1951 5 SheetsP-Sheet 2 BY M I %La/ ATTORNEY 11111630, 1936. c BROWN 2,045,695

CONTROL SYSTEM FOR CLASSIFICATION YARDS Filed July 31, 1931 5Sheets-Sheet 3 June 1936- N. c. L. BROWN 2,045,695

CONTROL SYSTEM FOR OLASSIFIATI ON YARDS Filed July :51, 1931 5 Sheets--She e t 4 Fle4.

/ZMM m ATroRNE'Y INVENTOR BY J June 30, 1936. N. c. 1.. BROWN 2,0 5 6CONTROL SYSTEM FOR CLASSIFICATION YARDS Filed July 51, 1951 5Sheets-Sheet 5 FIG. 6.

Patented June 30, 1936 Ned C. L. Brown, Scottsvllle, N. Y., alslgnor toGeneral Railway Signal Company, Rochester,

Application July 31,1931, Serial No. 554,282 22 Claims. (01. 104-26)This invention relates to control systems for railway trafliccontrolling devices and more particularly to a system for centrallycontrolling switches and car retarders in a railway classification yard.

In railway classification yard systems, a large number of track switchesare employed to properly route cars from a single in-coming track to alarge number of diverging tracks classified according to theirdestination. Track brakes or car retarders are also employed to preventexcessive speed over such switches or undue impact when coupling withother cars in their destination track. Such track switches and carretarders are usually power operated and controlled by operators who arelocated in one or more centrally located towers and set up routes toproperly direct each car to its classification track according toinformation furnished him by a previously arranged switch list. Theseswitch lists ive the initial and number of each car in the order ofarrival at the yard, their weight and the classification tracks to whichthey are assigned. The present type of control machines with which theoperator routes these cars consists of control panels having leveroperated contact means which are given numbers corresponding to thedevices which they control and the operator may associate such numberswith corresponding numbers of switches or retarders designated on aminiature diagram of the classification system.

In view of the above, it is proposed to provide an improved controlsystem in which the inconvenience and possible confusion due to thenecessity of associating switch numbers with their proper control leveris avoided by providing control devices directly associated with routesover a miniature representation of the device which they govern. It isalso proposed to provide indicating means in such control devices whichenables the status of the traffic controlling devices to be readilyapparent at all times and to provide a more convenient and eflicientmeans of manipulating the switch list used in such systems to therebyincrease the number of trafflc controlling devices over which anoperator may conveniently control traflic movements.

Other objects, purposes and characteristic fea- Fig. 1 is a diagrammaticshowing of a control panel for a typical classification yard arrangedaccording to this invention Fig. 2 is a control circuit diagram for asingle car retarder and a simple track switch in accordance with thisinvention;

Fig. 3 is a control circuit diagram for a lap track switch also inaccordance with this invention;

Fig. 4 is a sectional view of a proposed control push button to be usedin the above system also included as a part of the present invention;

Fig. 5 is a side view of two push buttons of the type shown in Fig. 4arranged to show their interlocked relation; and,

Fig. 6 is a diagrammatic showing of a proposed switch list holder andactuator also in accordance with this invention.

The control panel 1) shown in Fig. 1 may be mounted at a desk or thelike and constructed of suitable fiat material of a size which enablesthe operator to conveniently reach all parts thereof. The panel 0 isconspicuously marked by grooves or other means to represent the layoutof the actual track, and in this disclosure a typical system is assumedsuch as shown in Fig. 1. In this system shown, various classificationtracks numbered consecutively from 1 to 36 may be alined, by a series ofswitches, with a single in-coming track I.

The point at which each of the representations of track in Fig. 1diverges, represents a switch in the actual track layout, and each routeover such switch is represented by a push button Pi etc. which is solocated as to make its associated route readily apparent. Each carretarder unit is also represented in a corresponding position on thepanel 0 by five transversely spaced push buttons, each of which isarranged to effect different degrees of retardation.

It is now obvious that, with a system of push buttons thus arranged, adistinctive condition may be quickly set up which will represent thealining of a route to any one of the 36 tracks shown. It may be foundexpedient for the operator to start at the particular destination on thecontrol panel and depress all switch control push buttons which areincluded in a route from there to the in-coming track, as for example,if it is desired vto route a car to track 3|, push buttons Pl, P2, P3and P4 are depressed. The proper retarder push button to be depressed inthe various units included in such routes may be judged by the operatorfrom the weight of the car given on his switch list or by observing theactual speed at which the car is moving.

The manner in which these push buttons function to control the tramccontrolling devices is diagrammatically shown in Figs. 2 and 3, whichshow the push buttons in a very diagrammatic manner, as a manuallyoperable button M arranged, when depressed, to operate contact means andhaving an indicating lamp L included therein which is visible through alens or glass S in the top of the button M. These push buttons arebiased to an upper position and are interlocked by suitable means whichis clearly shown in Figs. 4 and 5 and which will be fully describedhereinafter.

Referring now to Fig. 2,a section of the operators control panel 0 whichincludes the controls for a simple switch and a car retarder is shownwith a diagrammatic illustration of each push button associated with itsposition thereon by dotted lines. A simple track switch TSI is shown asoperated by a switch machine SMI which is controlled by push buttons P5and P6 and a car retarder R. is illustrated as operated by a retardermechanism RM (shown as a dotted rectangle) which is controlled by thepush buttons P1, P8, P9, Pill and PI l.

A short track circuit Tl including the switch TSI is energized by asource of energy TBI and two relays TRI and TR2 are connected so as tobe selectively energized from this track circuit according to thepositions of the push buttons P5 and P6. These relays TR! and TR2 eachhave compound windings with one winding of each, Wi and W2, adapted topick up its armature when energized from the track section '1 and asecond winding of each, HI- and H2, arranged in series with the switchmachine operating circuit, is adapted to hold the armature up afterhaving been previously picked up by the first winding.

The push button P5 representing the normal route over the track switchTSI is shown depressed in Fig.2and the track switchTSl is shown asoperated to its normal position in accordance therewith. The indicatinglamp L5 in the push button P5 is thus energized over the followingcircuit:beginning at one terminal B of a source of energy, wires 31 and38, contacts 39 of the switch machine SMI bridged by a shunting block 40in its normal position as shown, wire 4|, lamp L5, wires 42 and 43,front point 44 and contact 45 of relay TRI, wires 45 and 41 to the otherterminal of the source of energy. The indicating lamp L5, beingenergized, then indicates directly on the operators control panel 0 thata normal route is alined over the track switch TSI and that the tracksection Ti is unoccupied.

If it is now desired to aline a reverse route over the track switch TSI,the push button P8 is depressed which sticks down and releases the pushbutton P5 which then returns to its upper position as will be describedhereinafter. Relay TRI, having been energized from the track section Tlover wire 48, contacts 49 and 50, wire 5|, winding WI and wires 52 and53, is now deenergized and relay TRZ is energized over the track circuitTl over 'ferring to the drawings.

13, contacts 14 and I5 bridged by a shunting block 15 in its normalposition, wire 11, motor field Fl wire ll winding C0 of the brake BR. tothe opposite terminal C of the source of energy. This causes the switchmachine SMI to operate the 5 track switch TSI to its reverse positionand shift the contact shunting blocks 40, I0 and 18 to their reverseposition in preparation for the return operation of the switch machine.

The shifting of the contact shunting block 40 10 deenergizes theindicating lamp L5 and energizes the lamp LG from the terminal B of theaforesaid source of energy, wires 31 and 19, contacts bridged by block40 in the reverse position, wire 8i, lamp L6, wires 82, 43 and 83, frontpoint 15 84 and contact 85 of relay TR! and wires 86 and 41 to theopposite terminal C of the source of energy. The energizing of theindicating lamp L8 now indicates to the operator that a reverse route isalined over the switch TSI and that the 20 track section TI is notoccupied. It is obvious that when the section TI is occupied both relayTRI and relay 'I'RZ will be deenergized and thereby extinguish bothindicating lamps by interrupting their common circuit at the parallelcontacts 45 and 85.

The operation of the switch TSI back to its normal position may ofcourse be accomplished by pressing push button P5 which in a similar wayreleases P6 and is effective to aline a normal 3n route in a mannerwhich is now obvious by re- It will also be noticed that if both pushbuttons P5 and P6 are pressed at the same time, P5 only will beeffective as the circuit ordinarily completed by P6 includes a con- 3:,

tact made only with P5 in an upper position.

To obviate the possibility of any operation oi the switch machine SMIwhen the track section TI is occupied, as by a short, or cross thefollowing shunt circuit on the switch machine 40 motor is established byboth relays TRI and TR2 deenergizedz-beginning at the terminal 0 of theoperating energy, contact 64 of relay TRZ deenergized, wire 65, contact66 and back point 61 of relay TRI deenergized, wire 68, contacts 45 89shunted by block 10, wires H and 12, armature Al, wire I3, contacts 14and 75 shunted by block 16, wire 11, field winding Fl, wire 18, wind ingC0 of the brake BR to the same terminal C of the operating energy. It isobvious that 50 with the switch machine SMI in its reverse position, asimilar shunt circuit is also established over the reverse controlcircuit whenever the track section TI is occupied.

Push buttons P'l, Pl, P9, PIU and Pi I are posi- 55 tioned on thesection of the control panel 0 to represent the location of the retarderR and may be arranged from the operators left to right to representvarious successive degrees of retardation as shown in Fig. 2. Theseretarder push 60 buttons may be of the same type and interlocked in thesame manner as those'used in the switch control previously described andare effective to selectively energize any one of five circuits leadingto the retarder mechanism RM. It will be 65 noticed also that thecircuit which each push button is arranged to complete includes seriescontacts on each button of lesser degree which contacts are made onlywith the buttons in the upper position. Thus, in the. event that more 7than one push button is depressed at the same time, only the lesserdegree button will be effective.

The. retarder mechanism represented by the dotted rectangleRM ma'yinclude an arrange- 7 ment such as shown in the patent to W. K. Howe No.1,757,428 dated May 6, 1930 in which the five push buttons of this caseare replaced by the manual control lever and'can be used in combinationwith relays, and-contactors shown In this patent to cause the retarder Rto assume any one of five positions in accordance with whichever pushbutton is depressed.

An indicating lamp in each push button is energized by a contact closedwhen the button is depressed and a relay SR is connected in series withthe common energy circuit to these push buttons which relay is. arrangedto extinguish all the retarder indicating lamps when energized by theretarder control current, or in other words, when a selected push buttonis depressed, the operating energy for the retarder mechanism RM flowsin series with the winding of the relay SR thus depriving all theindicating lamps of energy until this operating circuit is broken bycontacts in the retarder mechanism BM in a manner disclosed in the abovementioned patent. These indicating lamps then indicate directly on thecontrol panel the status of this retarder only when the retardermechanism has operated into correspondence with the selected position.

The control circuit shown in Fig; 3 uses apparatus which is similar tothat used in the simple switch layout in Fig. 2, but is arranged toselect any one of three routes by pressing push buttons associatedtherewith. In this arrangement, two overlapping track switches T82 andTS3 are respectively operated by switch machines SM2 and SM3 and theircontrol is effected by four relays TR3, TR4, TR5 and TR6 which areselectively energized from track circuit energy by push button PI2, PI3and PI4. Three track sections T2, T3 and T4 may be employed andrespectively energized by three sources of energy TB2, TB3 and T34, asshown. The central one of these sections T3 may control a relay CTRwhich is arranged to deenergize the relays TR3, TR4, TR5 and TR6 whenthis central section is occupied and it is obvious that the firstsection T2 controls relays TR3 and TR4 and likewise the last section T4controls relays TR5 and TR6.

The push button PI2 in the section of the control panel 0 is showndepressed and a left diverging route in accordance therewith is alinedby the switch TS2 in its reverse position. An indicating lamp LI2 in thepush button PI2 is accordingly energized over the followingcircuit:-beginning at a terminal B of a source of energy, wires 81 and88, contacts 89 of switch machine SM2 shunted by block 90, wire 9|, lampLI2, wire 92, front point 93 and contact 94 of relay CTR, wire 95, frontpoint 96 and contact 91 of relay TR3, and wires 98', 99, and I00 to theopposite terminal C of the source of energy.

The circuit which was effective to energize relay TR3 upon pushing thebutton PI2 is as followsz-beginning at a rail of the track section T2,wires I02, I03 and I04, push button contacts I05 and I06 closed, wireI01, winding W3 of relay TR3, wires I08 and I09, contact H0 and frontpoint III of relay CTR,-wire H2 to the opposite rail of the tracksection T2.

The relay TR3 being energized closes the following operating circuit forthe switch machine SM2z-beginning at the terminal B of a source ofenergy, wires H3 and H4, winding H3 of relay TR3, wire H5, front pointH6 and contact H1 of relay TR3, wire H8, contact H9 and back point I20of relay TR4, wire I2I, switch machine contacts I22 then shunted byblock I23 in its normal operated position, wires I24 and I25, switchmachine motor armature A2, wire I26, contacts I21 and I28 shunted byblock I29 in its normal operated position, wire I30, switch machinemotor field F2, wire I3I, winding C0 of the brake BR to the oppositeterminal C of the source of energy. This circuit being completed wasefiective to aline a left diverging route by operating the switchmachine SM2 to a reverse position thereby shifting its contact blocks90, I23, and I29 to the position now shown and complete the indicatingcircuit previously described.

Considering that it is next desired to aline a straight through route inthe layout of Fig. 3, the push button Pl3'on the operators panel 0 isdepressed which releases the push button PI2 and energizes the relaysTR4 and TR5. The

energizing circuit for relay TR4 may be traced 20 as follows:beginningat a rail of the track section T2, wires I02, I03 and I04, contacts I 05and I32 of push button PI2 in its upper position, wire I33, contacts I34and I35 of push button PI3 depressed, wires I36 and I31, winding W4 ofrelay 25 rail of the track section T4, 35

The return of push button PI2 to its upper position deenergizes relayTR3 by interrupting its circuit at contacts I05 and I06 and consequentlywhen the relay TR4 is energized the following normal operating circuitfor switch machine SMZ is completed:beginning at a terminal B of asource of energy, wires I I3 and I48, winding H4 of relay TR4, wire I49,front point I50 and contact I5I of relay TR4, wire I52, contact I53 andback point I54 of relay TR3, wire I55, contacts I56 of switch machineSM2 shunted by block I23, wires I51 and I26, motor armature A2, wireI25, contacts I58 and I28 shunted by block I29, wire I30, motor fieldF2, wire I3I, winding C0 of the brake BR to the opposite terminal C ofthe source of energy. The completion of this circuit results intheoperation of the switch machine SM2 to its normal position whichaccordingly shifts the shunting blocks 90, I23, and I29 to their normaloperation position which is opposite to that shown.

It will also be noted that the energizing of relay TR5 sets up a similarnormal operating circuit for the switch machine SM3 but as this switchmachine is already in such a position, no operation thereof takes place.The straight through route is thus alined with both switch machines SMZand SM3 in their normal position and the indicating lamp LI3 in the pushbutton PI3 is energized over the following circuit:beginning at aterminal B of a source of energy, wires 61 and I59, contacts I60 ofswitch machine SM2 shunted by block 90 in its normal operated position,wires I6I and I62, contacts I63 of switch machine SM3 shunted by block201 in its normal operated position, wire I64, indicating lamp LI3,wires I65, I66, and I61, front point I68 and contact I69 of relay TR5energized, and wires I10 and I00 to theopposite terminal C of the sourceof energy.

It is now obvious that a right div ging route may similarly be alined bypressing push button PI4 which is effective to energize relays T84 andTRO thereby establishing a normal operating circuit for switch machine8M2 and a reverse operating circuit for switch machine 8M0. Inasmuch asthese circuits-are similar to the ones dust traccd, it is not considerednecessary to trace them in detail.

When these switch machines 8M2 andBMl have assumed a position aliningthe aforesaid route, an indicating circuit is completed to theindicating lamp LI4 which includes contacts of switch machine 8M2 madein its normal operated position which contacts are in series withcontacts on switch machine 8M0 made in its reverse'operated position. Itwill be noted that when the track sections T2. T0 and T4 are occupied, ashunt is established on the operating motors of these switch machinesSM2 and 8M0 in the same general manner as in the simple switcharrangement previously described.

The arrangement illustrated in Fig. 3 shows a layout for routing cars inany one of three tracks by employing what is generally termed a lapswitch layout, but it is desired to be understood that this circuitarrangement may equally well be applied to the conventional three-throwor slip switch layout which is interchangeable with the overlaparrangement shown. In either of such layouts, i. e. the present lapswitch, and the alternative slip switch, a single track section toreplace sections T2, T3 and T4 may be employed to control a single trackrelay which in turn may deenergize the four relays TR3, TR4, PR5 and TRtwhen this track section is occupied, by means of this single relaysupplying energy through its front point to wires I00 and I42 inmultiple. It is obvious that such an arrangement although moreeconomical would not have the operating flexibility possessed by thethree track sections.

A proposed construction of a push buttdn P which may be employed in thepreviously described circuits is shown in the sectional view in Fig. 4and this single type of push button may be mounted on the operator'spanel in interlocked groups of two or more as illustrated in Fig. 5.This push button consists of a cylindrical button M having a cover glassS secured in its top by a threaded ring 202, and an insulating ring 203threaded and adapted to screw on to the lower end of the button M whenassembled. A frame member 204, havinga top cylindrical guide arranged toreceive the button M, has two downwardly extending sides which holdwaninsulating socket member 205 by through bolts 206. The button M may beinserted in the cylindrical guide in the frame member 204 and screwedinto the insulating ring 203 which then stops the downward motion of thebutton M by engaging an annular shoulder on the socket member 205 aswell as limiting its upward motion by engaging the lower end of theaforesaid frame guide. A compression spring 201 resting on the top ofthe socket member 205 engages the ring 200 thereby biasing the button Mupwardly.

The socket member 205 has a downwardly extending stem portion by whichit is held to the frame 204, and may also serve to hold resilientlymovable contacts 208 each side thereof which are biased to normallyengage resilient contacts 209 and are operable to engage similarcontacts 2I0. Two insulated resilient terminal strips 2 extend throughthe base of the socket 200 and sulating ring 200 forces the movablecontacts 200 ..insuiated body bushings (not shown).

movable contacts 200 extend into the path m the button M so that whendepressed, the ininto engagement with the fixed contacts 2" and out ofengagement with the contacts 200. A shaft 2 is rotatably held in theframe member 204 and is sufficiently long to include each push button inthe interlocked group. A locking dog D is secured to the shaft 2 at eachpush button by a pin HI and is biased inwardly by a spring I12. This dogD is so positioned that when the button M is depressed, the dog isforced outwardly by the insulating ring 200 thus rotating 2 the shaft 2and causing a corresponding motion of the other dogs attached thereto.When the button M has reached its extreme lower position, the lower endof the dog D clears the insulating ring 200 and is forced inwardly bythe 25 spring I12 to retain the button M in its lower position when thepressure thereon is removed.

Referring now to Fig. 5 which shows the right hand push button retainedin 'a depressed position as described above, it is obvious that when 30the left hand push button is depressed the looking dog thereon is forcedoutwardly which rotates the locking dog on the right hand push buttoncorrespondingly through the shaft 2 thereby releasing the right-handbutton and retaining the left-hand button depressed. It is seen that anynumber of push t ns may be interlocked in like manner so that when oneis depressed, any others which are then retained depressed will bereleased, thus making effective only the last selected push button inthe group.

The apparatus shown in Fig. 6 shows diagrammatically a proposed meansfor manipulating the switch list by which the operator is guided inrouting the cars over the system. This list should be mounted in aconvenient location preferably at a point above the control panel whereit may be conveniently read by the operator. A side view of such aswitch sheet is shown as X in Fig. 6 which may be of any convenient sizeand should include the necessary information concerning each car to beclassified in spaced horizontal lines thereon.

It is proposed to actuate this list X between a large roller I13 and asmall roller I14 each time a car is disposed of by being released overits route. The small roller I14 is rotatably sup ported at the ends ofarms I10 which are biased by' a spring I10 to hold the list X againstthe large roller I13. The large roller I10 is mounted on a shaft I11 bywhich it is rotatablyheld in bearings (not shown) and the ends of thisshaft I11 may have knobs I10 secured thereto by pins I19 whereby it canbe manually turned.

A ratcheting arm I00 is rotatably held on the shaft I11 and carries adouble pawl IOI which is engageable with teeth on a ratcheting wheel I02secured against rotating motion to the shaft I11. This double pawl IOIis biased by an over center buckling spring I03 to engage either thelower end or the upper end thereof with the teeth of the wheel I02according to which side of center the spring I00 is manually buckled.This spring I00is arranged to absorb the ratcheting motion of the pawlIII in either of the above mentioned positions without being bent to abeyond-center position, which thereby provides a resilient biasing meansfor the pawl I8] as well as a means for manually shifting the directionof ratcheted motion of the roller I13.

A pedal means for actuating the ratcheting arm I80 is provided by apivoted pedal I84 which operates to force the arm I80 upward through aconnecting rod I85, and a spring I88 is included to return the arm I80to a lower'position. An electro-magnetic means for lifting the arm I80is also provided by an electro-magnet I81 operating an armature I88connected to the arm I80 by a link I88. This electro-magnetic means maybe controlled manually by a push button I80 arranged to energize theelectrmmagnet I81, as shown, and this push button may be convenientlylocated on or near the operator's control panel.

It is also proposed to provide an automatic means for actuating theratcheting arm I80 by a track treadle I9I which is operated by eachwheel of a car passing thereover. This treadle I9I may be located at thein-coming track, such as I in Fig. l, and is employed to close anelectrical circuit to an electro-magnet I92 which operates a ratchetwheel I83 by an armature I94 biased by a spring I85 and having a pawlarrangement I96 attached thereto. The ratcheting wheel I93 has a dog I91operating to permit'only uni-directional rotation thereof and has a camwheel [98 attached thereto which is arranged to lift the ratcheting armI80 through an extension I80 thereon once for every four operations ofthe electro-magnet I92 thereby ratcheting the roller I13 one space forevery car, i. e. every four wheels, passing over the track treadle I9I.

A manual cut-out switch I99 which opens the circuit controlled by thetrack treadle I8I is provided to disconnect the automatic means justdescribed when it is desired to operate the ratchet by either the manualor the pedal means. It is obvious that either the automatic, the manualor the pedal means can operate the ratchet arm I80 which in turn cannotch the roller I13 one space in either direction through the pawl II,which direction is effected by the selected position of the spring I83.To retain such forward ratcheted motion of the roller I13, a resilientdetent 200 is provided which exerts a retaining force on the roller I13when resting between the teeth thereon, as shown.

A classification yard control system has thus been disclosed which isextremely simple in its operation, which provides readily apparent meansfor indicating the status of each controlled device thereof, which has acontrol panel with so compact control apparatus thereon that a completesystem may be conveniently controlled by a single operator, and to avoidconfusion of the operator, such control apparatus is so located on aminiature representation of the actual track layout that their functionis readily associated therewith and to further increase the efliciencyof the system an accurate and time saving means for manipulating theoperator's switching sheet is also provided. And the present inventionhas further disclosed as an economic feature, a unit push button whichmay be assembled in the required groups to thereby increase theflexibility of the system.

In describing the present invention, attention has been directed to onespecific embodiment thereof, without attempting to point out the variousalternate or optional features of construction, or the diflerentorganizations or combinations that may be employed. For example, the Qcurrent supplied to the track sections in Fig. 2 and Fig. 3 is shown asa battery but an altemating source of current may as well be used byemploying the conventional transformer and rectifler arrangement, andindication selectors such as conventionally used in interlocking withsuitable windings thereon may be substituted for the relays TRI, TR2,etc. The specific construction of the push button shown is also merelysuggested as one way in which a device may be made which will functionas required in the system disclosed herein. Other types of switchmachines may also be employed in this system, such as the well knowntype which does not include the magnetic brake as shown herein, butrelies upon dynamic snubbing which may be obtained by making slightchanges in the control circuits all of which is well known in the art.

In other words, the particular embodiment of the present invention hasbeen selected to facilitate in the disclosure thereof rather than tolimit the number of forms which it may assume, and it is desired to beunderstood that various modifications, adaptations and alterations maybe applied to the specific form shown to meet the requirements ofpractice, without in any manner departing from the spirit or scope ofthe present invention except as limited by the appended claims.

Having thus described my invention, what I claim is:-

1. In a control system for classification yards, in combination, aclassification yard, a control panel marked to simulate the layout ofsaid classification yard, switch control push buttons arranged torepresent routes over switches on said control panel, car retardercontrol push buttons arranged on said control panel inprogressiveorderof retardation at a location thereon to simulate the location of theassociated car retarder, individual contacts operated by said pushbuttons to selectively energize circuits which are effective todistinctively operate associated traflic controlling devices, means ineach push button arranged -to indicate when the condition of theassociated trafflc controlling device corresponds thereto, and meansinterlocking the push buttons associated with each traflic controllingdevice whereby any one of such interlocked push buttons is retaineddepressed and is released by a subsequent depression of another pushbutton interlocked therewith.

2. In a control system, a miniature track diagram, push buttons on saidtrack diagram arranged to represent various conditions of traificcontrolling devices in said system, means interlocking the push buttonswhich are associated with each trafiic controlling device whereby adepressed push button is retained in such a position until released bythe depression of another push button interlocked therewith, contactsoperated by the depression of said push buttons,

mal route over each track s ,vitch thereon, a push button arranged torepresent a reverse route over each track switch thereon, a switchmachine operably connected to each of said track switches, a normal anda reverse control relay associated with each of said switch machines,said control relays having an operating winding and a holding windingthereon, track circuits extending through each track switch in saidsystem, said track circuits including contacts operated by an associatednormal control push button and contacts operated by an associatedreverse control push button whereby either an associated normal controlrelay or an associated reverse control relay may be selectivelyenergized, a normal and a reverse operating circuit for each of saidswitch machines each of which operating circuits includes a seriesholding winding and anenergized contact of the associated control relayand a deenergized contact of the other control relay and shuntingcircuits for the operating motor of said switch machines effective whenboth the associated normal and reverse control relays are deenergized.

4. In a control system, a track switch power operated by a switchmachine, a miniature representation of said track switch, a push buttonon said miniature representation arranged to simulate a normal routeover said track switch, a push button on said miniature representationarranged to simulate a reverse route over said track switch, a tracksection including said track switch, a track circuit completed-by saidnormal push button in a depressedposition including the rails of saidtrack section, contacts of said normal push button and windings of anormal control relay for said switch machine, and a track circuitcompleted by said normal push button in an upper position and saidreverse push button in a depressed position including the rails of saidtrack section, contacts of said normal push button, contacts of saidreverse push button and windings of a reverse control relay for saidswitch machine.

5. In a control system for classification yards, a car retarder, acontrol panel having a group ofpush buttons located with respect to aminiature track diagram thereon to simulate the location of said carretarder, individual contacts operated by said push buttons, a source01' energy, control,circuits for said car retarder associated with eachof said push buttons and are ranged to be selectively connected withsaid source of energy by the depression of said associated push button,said push buttons being arranged to represent various progressivedegrees of retardation of said car retarder, said control circuitsincluding series contacts of each push button representing lesserdegrees of retardation and said series contacts being made with saidlesser degree push buttons in an upper position.

6. In a control system for classification yards, a car retarder, acontrol panel having a group of push buttons representing variousdegrees of retardation of said car retarder, a source of energy, controlcircuits for said car retarder selectively connected to said source ofenergy by the depression of the associated push button, a relayconnected in series with said source of energy and said controlcircuits, indicating means associated with each of said push buttons andhaving individual energizing circuits including contacts on itsassociated push button closed during depression thereof and each of saidindicating circuits being-interrupted by contact means on said seriesrelay when energized.

'7. In a control system for railroad yards, a track switch poweroperated by a switch machine. a control panel, a normal control push 5button on said control panel arranged to effect the normal control ofsaid switch machine, a reverse control push button on said control panelarranged to effect the reverse control of said switch machine,individual indicating means in 10 said normal control push button and insaid re-, verse control push button, circuit means energizing saidnormal indicating means when said switch machine is in its normaloperated position, circuit means energizing said reverse indiis eatingmeans when said switch machine is in said reverse operated position, anda track circuit arranged to control both said normal indicating circuitmeans and said reverse indicating circuit means.

8. In a control system for railroad yards, a section of railroad trackconstituting a straight through route and having a power operated trackswitch therein controlling a right hand diverging route therefrom and apower operated track 25 switch-therein controlling a left hand divergingroute therefrom, a miniature representation of said section of railroadtrack, individual push buttons on said miniature representation arrangedto' simulate said right hand diverging route, said left hand divergingroute and said straight through route over said section of track,insulated track sections individually including said track switches, asource of energy at one end of each section, a normal control relay anda reverse control relay associated with each of said power operatedswitches, control circuit means whereby said relays may be distinctivelyenergized from said associated track sections in accordance with adepressed push button, operating circuits for the switch machines, meansarranged to distinctly operate said switch machines in accordance withthe energization of said associated control relays and a shunt for eachoperating circuit effective when both of the associated control relaysare deenergized.

9. In a railway control system, a three-way track switch arrangementpower operated by switch machines, individual push buttons correspondingto the three routes over said switch arrangement, track circuitsincluding said switch arrangement, a normal and a reverse control relayfor each of said switch machines, energizing circuits for said controlrelays including said track circuits whereby said control relays may beselectively energized by depression of said push buttons, indicatingmeans in each of said push buttons, individual energizing circuits forsaid indicating means including contacts on said switch machines madewhen the condition of said 60 switch machine is in accordance with theroute represented by the push button and contact means interrupting saidindicating circuits when ticular trafllc controlling device beinginterlocked whereby the operation of one contact means releases othercontact means interlocked therewith and retains said operated contactmeans. 7 5

11. In a control system for railway yards, a miniature diagram of a yardhaving manually operable contact means each so locatedon said diagram asto simulate a condition of a trafllc controlling device associatedtherewith, said contact means being interlocked with other contact meansassociated with the same trafllc controlling device and havingindividual indicating lights therein visible on said miniature diagram.

12. In control systems for railway yards, in combination, a miniaturediagram of an actual yard having a trafllc controlling device, aplurality of control means on the diagram for governing the said device,the control means being so located on the diagram as to simulate acondition oi. said device, each control means being movable to operatedposition against biasing means, and interlocking means for the pluralityof control means whereby operation of one control means releases all theothers and retains the operated one in operated position. i

13. In control systems for railway yards, in combination, a miniaturediagram of an actual yard having a traiilc controlling device, aplurality 01' control means on the diagram for governing the saiddevice, the control means being so located on the diagram as to simulatea condition of said device, each control means being movable to operatedposition against biasing means, and interlocking means for the pluralityof control means whereby operation of one control means releases all theothers and retains the operated one in operated position, a circuitcontrolled by each control means and arranged so that but one circuitcan be effective at any one time to affect the traflic controllingdevice.

14. In a control system for railway systems, in combination, aninsulated track section, a device associated with the section,ope'rating means for the device, control circuits for the operatingmeans, a track circuit including the track section and a plurality oftrack relays, a corresponding plurality of manually operable controlmembers, the control circuits being controlledby the track relays, andthe track relays being controlled by the control members.

15. In a control system for railway systems, in combination, aninsulated track section, a device associated with the section, operatingmeans for the device, control circuits for the operating means, a trackcircuit including the track section and a plurality of track relays, acorresponding plurality of manually operable control members, thecontrol circuits .being controlled by the track relays, the track relaysbeing controlled by the control members, a holding winding on eachrelay, each control circuit including a back point or a track relay anda holding winding of a different track relay.

16. In a control system for railway systems, in combination, aninsulated track section, a device associated with the section, operatingmeans for the device, control circuits for the operating means, a trackcircuit including the track section and a plurality of track relays, acorresponding plurality of manually operable control members, thecontrol circuits being controlled by the track relays, the track relaysbeing controlled by the control members, an operating winding on eachtrack relay, an energizing circuit for the operating winding of onerelay including only a contact controlled by one of the control members,and an energizing circuit for the operatingwinding of another relayincluding, in series, contacts controlled by a plurality of the controlmembers.

17. In a control system for railway systems, in

combination, an insulated track section, a deof a track relay and aholding winding of a difterent track relay, an operating winding on eachtrack relay, an energizing circuit for the operating winding of onerelay including only a contact controlled by one of the control members,and an energizing circuit for the operating winding of another relayincluding, in series, contacts controlled by a plurality of the controlmembers.

18. In a railway track switch layout, two overlapping track switches, apower operated means for operating each switch respectively, a firstpair of translating devices for controlling one of the means, a secondpair of translating devices for controlling the other means, a pushbutton arranged to jointly control one device of each pair of devices, apush button arranged to control the other device of one pair, and a pushbutton arranged to control the other device of the other pair.

19. In a railway track switch layout, two overlapping track switches, apower operated means for operating each switch respectively, a firstpair of translating devices for controlling one of the means, a secondpair of translating devices for controlling the other means, a pushbutton arranged to jointly control one device ofeach pair of devices, apush button arranged to control the other device of one pair, a pushbutton arranged to control the other device of the other pair, andindicating means in each button to indicate the response of a poweroperated means to its button.

20. In a railway track switch layout, two overlapping track switches, apower operated means for operating each switch respectively, a firstpair of translating devices for controlling one of the means, a secondpair of translating devices for controlling the other means, a pushbutton arranged to jointly control one device of each pair of devices, apush button arranged to control the other device of one pair, a pushbutton arranged to control the other device of the other pair, meansretaining each button in depressed position upon being depressed,andmeans releasing the retaining means of any depressed button, upondepressing another button.

21. In a railway track switch layout, two overlapping track switches, apower operated means for operating each switch respectively, a firstpair of translating devices for controlling one of the means, a secondpair of translating devices for controlling the other means, a pushbutton arranged to jointly control one device of each pair of devices, apush button arranged to control the other device of one pair, and a pushbutton arranged to control the other device of the other pair, a normaland a reverse operating circuit for each power operated means, thenormal operating circuits for both power operated means being completedby the depressing of the button which controls two of the translatingdevices.

22. In a railway track switch layout, two overlapping track switches, apower operated means for operating each switch respectively, a firstpair of translating devices for controlling one of the means, a secondpair of translating devices for controlling the other means, a pushbutton ar ranged to jointly control one device of each pair of devices,a push button arranged to control the other device of one pair, a pushbutton arranged to control the other device of the other pair,

and indicating means in each button to indicate the response 0! a poweroperated means to its button, a normal and a reverse operating circuitfor each power operated means, the normal operating circuits for bothpower operated means being completed by the depressing of the buttonwhich controls two of the translating devices.

NED C. L. BROWN.

